Metal furniture constructed from lock-seam tubing



P. H. FRIEL.

METAL FURNITURE CONSTRUCTED FROM LOCK SEAM TUBING.

- APPLICATION FILED APR. 12, I917.

1,337,128, 5 Patented Apr. 13, 1920.

UNITED STATES PATENT OFFICE.

PATRICK H. FRIEL, OF KENOSHA, WISCONSIN, ASSIGNOR- TO ALFRED TERRELL, OF KENOSHA, WISCONSIN.

METAL FURNITURE CONSTRUCTED FROM LOCK-STEAM TUBING.

Specification of Letters Patent.

Patented Apr. 13, 1920.

Continuation of application Serial No. 69,284. filed December 29, 1915. This application filed vApril 12,

To all whom it may concern Be it known that I, PATRICK H. Fnmn, a citizen of the United States, residing at Kenosha, in the county of Kenosha and State of ld isconsin, have invented certain new and useful Improvements in Metal l urniture Constructed from Lock-Seam Tubing, of which the following is a specification.

This invention relates to improvements in metal furniture constructed from lock seam tubing, and relates more specifically to means affording a supplementary locking of the interlocked seam portions, and as a further feature of improvement embodying such supplementary locking means as a structural element of an article of furniture. he invention finds its chief and most important field when embodied in or incorporated with thin-walled metal tubing of the lock seam variety.

In the making of tubular metal bedsteads and analogous furniture constructions it is very usual to form marginal frames of thin-walled lock seam tubing having curved or bent portions, and it is also very 'usual to provide interspaced spindles extending between larger frame members.

It is well known that thin-walled lock seam tubing is considerably weaker, especially as regards torsional stresses, than seamless tubing of the same gage or thickness; the weakness being due, not to any lack of positive tying together of the meeting edges of the tube shell, or to any weakening of the shell per 86 along the line of the lock seam, but due to the fact that the members of the lock seam are susceptible of sliding movement longitudinally upon each other. Thus, for example, a lock seam tube may be quite easily twisted so as to distort its seam which is normally parallel with the axis into a spiral relation thereto. lVith a seamless piece of tubing it is, of course, impossible to so twist the tubing appreciably without rupturing it.

In metal furniture, and notably in bedsteads, rigidity is a matter of prime importance, and a high degree of rigidity cannot be secured where the structure is composed of lock seam tubing made in the ordinary way.

By means of my present invention I overcome the lack of rigidity in look seam tub- Serial No. 161,474.

ing by positively looking or securing the parts of the seam against relative sliding movement upon each other. In the particular embodiment of the invention illustrated I also utilize the elements or devices which accomplish the locking of the seams as connecting elements for structurally uniting certain frame parts. 1

The invention will be readily understood from the following description, reference being had to the accompanying drawing, in which the invention is shown as incorporated with and embodied in a bedstead end frame.

Referring to the drawing- Figure 1 is a view in elevation of a bed stead end frame, certain parts being broken out, and shown in section to more fully disclose the details of construction;

Fig. 2 is a fragmentary detailof a portion of one of the main frame members with a ferrule socket attached, and showing par ticularly the relation of said socket and the attached means therefor to the lock seamof the main frame;

Fig. 3 is an axial sectional view taken in the plane of the center of the lock seam;

Fig. 4,- is a crosssectional view taken on line at of Fig. 2, but enlarged as compared with the latter;

Fig. 5 is a detail similar to Fig. 2, except that in this instance the ferrule socket is secured by two screws instead of one, and is larger.

Referring to the drawings, 1 designates as a whole the bedsteadendframe, 2, Qthe post portions thereof, and :5 the top rail; the posts and top rail being in this instance formed in a single piece. -l designates the cross frame member, which is parallel with the main part of the top rail and between which two members sgindles extend. The numeral 6 designates the several ferrule sockets, secured to the top rail and bottom cross frame member, respectively, in vertically opposed relation. Similar sockets, applied to the posts 2, receive the ends of the cross frame 4.

These ferrule sockets 6, are drawn sheet metal caps having cylindric side walls and substantially closed integral base end walls 9, which latter are preferably and as shown herein conformed to the contour of the tubular frame member to which said ferrule sockets are applied. In the present instance the ferrule sockets are shown applied to round tubing, and their base ends are therefore concavo cylindric externally. Through the base end of each ferrule socket there is formed one or more apertures to receive securing screws 8.

The thin walled lockseam tubing used in the frame construction shown is externally smooth, but is provided internally with a lock seam 10. This lock seam forms a rib upon the interior of the tubing of multiple tl'iickness'and the line of the seam is visible externally as a cleft 7 Such tubing, as usually formed and as shown in the present instance, is made by turning the edges of the tube blank inwardly and away from each other, so as to form oppositely disposed hook-like flanges 11 (see F 1g. 4-), which flange portions are embraced. by an enveloping strip 12, the edges of which are interposed between the flanges 11 and the overlying wall of the tube, as shown clearly in said Fig. 4. In this particular construction, as in most lock seam tubing, there is an external sea-m cleft, and moreover the parts of the tubing which form the seam are not locked with absolute rigidity against longitudinal movement upon each other. Thus, for example, a piece of such lock seam tubing may be twisted with comparative case because the lock seam permits the necessary slipping movement which accompanies a twisting of the tube.

In the specific embodiment of my invention shown herein the marginal frame members 2, 3 and 4, are so made that the lock seam joint is at the inside of the frame and inthe plane of the spindles 5. Accordingly, the ferrule sockets are applied so as to exactly overlie the lock seam, and, asclearly shown in the several detailed figures, apertures are formed through the multiple thicknesses of the seam and tapped to receive the securing screws 8. These tapped apertures intersect the seam'cleft 7 so that when the screws are set'in place they not only unite the ferrule sockets rigidly to the frame member but they also act as keys which absolutely prevent longitudinal movements of the seam parts upon each .other. Inother words, those portions of the opposed frame members 3 and 4 which have the ferrule sockets applied to them are, by the presence of the securing screws 8, made practically as rigid against twisting stresses as though formed of seamless tubing. The securing screws 8 thus perform the double function of key-locking the lock seams and of securing the ferrules to the tubing.

After the ferrule sockets have been applied to the respective frame member 3 and 4. and made rigid with the latterby means of the screws 8, the bedstead frame is assembled by first forcing the ends of the spindles tightly into one or the other of the set of ferrule sockets, then forcing the opposite ends of the spindles tightly into the opposed set of ferrule sockets, then springing the posts 2 far enough apart to permit the insertion of the cross frame members 4: in the ferrule socket 6 of the posts,.and finally pressing the latter together to tightly seat the ends of the said cross members in their ferrule sockets.

It will, of course, be understood that the form of lock seam shown is not an essential feature ofthe invention, it being a wellknown factthat other forms of lock seams are employed in the manufacture of tubing, and it being obvious that my invention, so far as it relates to supplementally locking such seams, is equally applicable to such other forms. So far as I am aware it is broadly new and original with myself to effect the locking of the parts of a lock seam against longitudinal displacement in tubul of this character and at the same time and by thesame means effect the attaclnnent or securing of a structural part to'the tubing. Accordingly, the appended claims are to be construed as not limited to the specilic construction shown and described in tl application. V

This application is a continuation of my application Serial No. (39,28el, filed Dec. 29, 1915.

I claim- V In an article of furniture, or the like, incorporating lock-seam tubing, a joint or union between parts thereof, comprising a member applied to a length of said tubing and overlying the lock-seam thereof, and means structurally uniting said member to said tubing and serving also to intersect the lock-seam and lock the interfolds of the latter positively against relative sliding movement. i

PATRICK n. FBIEL. 

